Search results
Results From The WOW.Com Content Network
Very weak electromagnetic fields disrupt the magnetic compass used by European robins and other songbirds, which use the Earth's magnetic field to navigate. Neither power lines nor cellphone signals are to blame for the electromagnetic field effect on the birds; [ 89 ] instead, the culprits have frequencies between 2 kHz and 5 MHz.
In the space environment close to a planetary body with a dipole magnetic field such as Earth, the field lines resemble a simple magnetic dipole. Farther out, field lines can be significantly distorted by the flow of electrically conducting plasma , as emitted from the Sun (i.e., the solar wind ) or a nearby star.
The simplest magnetic field B is a constant one– straight parallel field lines and constant field intensity. In such a field, if an ion or electron enters perpendicular to the field lines, it can be shown to move in a circle (the field only needs to be constant in the region covering the circle).
The initial theory proposed in 2014 was that—due to the tilt in Earth's magnetic field axis—the planet's rotation generated an oscillating, weak electric field that permeates through the entire inner radiation belt. [26] A 2016 study instead concluded that the zebra stripes were an imprint of ionospheric winds on radiation belts. [27]
The joined field lines are swept back over the poles into the planetary magnetic tail. In the tail, the field lines from the planet's magnetic field are re-joined and start moving toward night-side of the planet. The physics of this process was first explained by Dungey (1961). [6] As such, the process is now referred to as the Dungey Cycle.
Magnetic north versus ‘true north’ At the top of the world in the middle of the Arctic Ocean lies the geographic North Pole, the point where all the lines of longitude that curve around Earth ...
The magnetic field of a magnetic dipole has an inverse cubic dependence in distance, so its order of magnitude at the earth surface can be approximated by multiplying the above result with (R outer core ⁄ R Earth) 3 = (2890 ⁄ 6370) 3 = 0.093 , giving 2.5×10 −5 Tesla, not far from the measured value of 3×10 −5 Tesla at the equator.
In a new report from NOAA, the "World Magnetic Model" for 2020 is revealed, and it shows that the pole is speeding toward northern Russia. That trend, however, is expected to change.